Factors influencing persistent organic pollutant concentrations in the Atlantic white-sided dolphin (Lagenorhynchus acutus)

Authors

  • Karen J.S. Tuerk,

    1. Department of Environmental Health and Sciences, University of South Carolina, Columbia, South Carolina 29205, USA
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  • John R. Kucklick,

    Corresponding author
    1. National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, South Carolina 29412, USA
    • Department of Environmental Health and Sciences, University of South Carolina, Columbia, South Carolina 29205, USA
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  • Wayne E. McFee,

    1. National Oceanic and Atmospheric Administration, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston, South Carolina 29412, USA
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  • Rebecca S. Pugh,

    1. National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, South Carolina 29412, USA
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  • Paul R. Becker

    1. National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, South Carolina 29412, USA
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  • Certain commercial equipment or instruments are identified in this paper to specify adequately the experimental procedures. Such identification does not imply recommendations or endorsement by the National Institute of Standards and Technology, nor does it imply that the equipment or instruments are the best available for the purpose.

Abstract

Assessing the trends of persistent organic pollutants (POPs) in cetaceans is difficult because of age and gender influences on accumulation. Persistent organic pollutants bioaccumulate and are poorly metabolized; hence, concentrations may increase with age in males while females reduce their POP burden through parturition and lactation. Age and gender effects on contaminant concentrations are species specific because of life history and reproductive strategies. These influences must be understood in order to elucidate and assess lifetime POP exposure. The objectives of this study were to determine baseline POP concentrations in blubber samples from the Atlantic white-sided dolphin (Lagenorhynchus acutus) and to investigate life history and other influences, such as metabolism, on these concentrations. Forty-seven L. acutus blubber samples collected from mass stranding events in Massachusetts, USA (1993–2000), and archived in the National Marine Mammal Tissue Bank at the National Institute of Standards and Technology (Gaithersburg, MD, USA) were analyzed for 55 polychlorinated biphenyl congeners (PCB; 55 congeners), five polybrominated diphenyl ether (PBDE) congeners, and organochlorine pesticides (toxaphene, DDT and metabolites, mirex, dieldrin, chlordanes, hexachlorocyclohexanes, hexachlorobenzene, and endosulfans) by gas chromatography/mass spectrometry (GC-MS). Ages for 19 animals were determined from growth layer groups on decalcified, stained thin tooth sections. Total PCBs (ΣPCB; sum of 55 congeners) were the contaminants present in the highest concentrations in all age classes (0.5–63 μg/g wet mass) followed by sum of DDTs (0.50–43 μg/g wet mass), toxaphene (0.055–31 μg/g wet mass), chlordanes (0.30–24 μg/g wet mass), and PBDEs (0.12–4.0 μg/g wet mass). Body length had a greater statistical influence than age on contaminant burdens in L. acutus. Contaminant burdens decreased with length in both male and female L. acutus, suggesting metabolic elimination and/or growth dilution in males and off-loading via lactation in females.

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